Automatically adjusting shaker head harvester with steering correction and improved shaker head mounting

ABSTRACT

A harvester incorporating at least one force balanced shaker vibratory brush as the harvesting apparatus uses a sensing system connected to a plurality of spring feelers carried on a shaft to generate a torque value responsive to the location of the shape and position of a tree. The feeler springs may be of differing lengths to assist in tuning the harvester. Apparatus and a method for mounting the shaker head on the vehicle as well as system of steering the harvester are disclosed.

BACKGROUND OF THE INVENTION

[0001] I. Field of the Invention

[0002] This invention concerns an automatically adjusting, tree contourtracking, force-balanced shaker brush harvester apparatus for removingfruit from a tree, bush or plant, and methods of harvesting the fruit,controlling the position of the shaker heads and mounting the shakerbrushes in the harvester. This invention also includes a mechanism foran automatic control system for the directional control of the steerablewheels of the harvester.

[0003] The particular harvester of this invention is a type thatstraddles a row of crop, for instance, a row of olive trees in anorchard. It is know as an “over-the-row” harvester. It has an elevatedframe supported on four wheels and enough width between the wheels toaccommodate the orchard trees. For an orchard harvester the supportingframe may be more than eight feet off the ground to allow the harvesterto straddle a tree that is wide and tall. The harvester includessubstantially vertical shaker brushes having rod or tines that arepositioned into the branches of the tree to induce a vibration in thetree. This causes the fruit to be shaken off the tree.

[0004] The vibration is generated by a force-balanced drive for eachshaker head.

[0005] In a particular embodiment of this invention, the automaticallyadjusting shaker, harvester or the like has a series of leaf springscantilevered from a central pivot to act as tree contour sensingfeelers. The feelers are mounted to a support collar and clamped to ashaft. Their position is adjustable horizontally, vertically, and inlength—by replacing a first leaf spring of one length with a second leafspring of a different length—, to profile the general tree, bush orplant shape, e.g. a conical shaped tree profile. The feelers areadjustable depending on the tree, bush or plant shape profile. Forexample, the tree profile may comprise more of a vertical hedgerow shapewithout gaps between the trees. In this situation the length of thefeelers may be adjusted. That is, at least some of the feelers areadjusted to be shorter than they would be when set up for picking from aconical shaped tree.

[0006] An electrical rotation sensor, such as a potentiometer oralternatively, a linear sensor, is coupled with the shaft that supportsthe springs or feelers. The sensor detects movement of the springs (alsoreferred to as “feelers”, “spring feelers”, “feeler springs”) carried onthe shaft that causes a signal to be sent to a controller. Thecontroller in turn causes a proportional valve to reposition the shakerbrush, moving the shaker brush inwardly or more outwardly as needed. Therepositioning of the shaker brush drives a potentiometer error signaltoward zero, which thus establishes a new equilibrium point between thepotentiometer sensing feeler spring supporting shaft position and shakerbrush position. This allows for adjustment of the shaker depending onthe shape of the tree.

[0007] A “time-out” feature is used to shut off hydraulic pressure tothe actuator that moves the shaker brush in and out when a constantretract error occurs for more than a set time, e.g. ten seconds. Aconstant retract (of the shaker brush) condition will occur when theharvester is at the end of a tree row, if there are large distancesbetween trees, or if the harvester is stationary between trees, forinstance. When the harvester is at an end of a row the new course takenby the harvester will be void of trees and therefore no sensing isneeded. Thus, the spring feelers will, through the sensor carried on theshaft, indicate a “too wide” spacing error between opposed sets ofshaker brushes and attempt to retract the shaker head until the errordisappears.

[0008] After the harvester completes its turn or otherwise starts downthe orchard row the error signal will disappear as the spring feelerhost shaft will rotate in response to the feeler springs contacting thetree.

[0009] The attendant potentiometer will provide an output to thecontroller. The on board tree sensing and shaker brush adjusting controlsystem will process the output and cause an associated brush actuator, ahydraulic ram, to reposition the shaker brush relative to the sensedtree. The control signal will thus have changed from “retract” to“extend” and the shaker brush will be repositioned accordingly.

[0010] For normal travel within the operational parameters of theplacement in the orchard, a limit switch or alternatively, a mechanicalstop, may be implemented to interrupt a retract signal. The retractsignal, overridden by the limit switch, will position the shaker head ata preset position to prevent the shaker head from fully retracting.

[0011] Moreover, when the harvester is in a transport mode, where notrees, bushes or plants are to be engaged, the operator can override thelimit switch or alternatively override the mechanical stop. Thus, theshaker brushes will remain fully retracted. This results in minimizationof the width dimension of the harvester allowing for travel that is moreefficient.

[0012] The shaker brush position, which is normally controlled duringthe harvesting operation by the electronic control system, i.e. thecontroller, operating various hydraulic valve circuits of the harvester,can also be controllable by the harvester operator. He can manuallyswitch the shaker brush control from an “auto” mode to a “jog” mode. Inthe jog mode, the operator of the harvester can use a jog switch to moveand hold each individual shaker brush at a desired position within arange of parameters.

[0013] This invention also concerns an automatic steering correctionsystem for a harvester. It is usual to have a harvester equipped with apair of rail sensors affiliated with a pair of front guide rails. Asecond pair of rail sensors, located at the rear of the harvestervehicle, is used in this invention to indicate the position of the backend of the harvester. The harvester operator is alerted when the rearwheels are being steered automatically by the control system withindicator lights in the cab of the vehicle. Such automatic steering willhappen when the rear guide rail sensors send a signal to the controllerthat the harvester is not tracking the tree row evenly. Alternatively,the vehicle itself can be programmed to react to an unusual steeringsituation by an input to a manual input device, for instance, a keyboardinput device, that can be used to program the automatic control system.In essence, there is a semi-automatic operation where the operatorreceives sensory input from the system or fully automatic steering wheresteering corrections are made automatically without operator control.

[0014] II. Description of Related Information

[0015] In one style of harvesting, it is known to remove fruit, such asgrapes, nuts, citrus fruit and olives, from vines or trees using ashaker brush powered by a force balanced shaker. Present machines traveldown one side of a row of trees and harvest olives from that side of thetrees. A more complex type of harvester, an “over-the-row” machine,straddles the tree or vines. The profile of the tree is generallyconical in shape with appropriate spacing between the trees to allow forthe harvesters, tree trimmers, and workers, to complete the worknecessary to harvest the crop and maintain optimum health of the trees.

[0016] To pick the olives effectively, it is necessary to move theshaker head, in a single head unit that harvests from one side of thetree at a time, or in an over-the-row harvester where two opposed shakerheads are used, toward and away from a tree row centerline to properlyengage shaker rods or tines (which make up tree contacting elements ofthe “shaker brushes”) with the tree as the harvester travels along therow. The trees have what may be termed a front side, that portion of thetree on the side being approached by the harvester shaker and a backside of the tree on the side of the tree away from the approachingharvester. Good shaker contact with the side of the tree is easy. Goodshaking contact with the front and the backside of the tree is moredifficult. To accomplish harvesting with the shakers known in the art,more typically, harvesters that have only one shaker brush and harvestfrom the side, the shaker positioning is manually controlled. Startingbetween trees, the shaker is moved inward at the front side of the treetoward the tree row centerline. As the leading side of the shakerengages the tree it must be rapidly pulled outward away from the treecenterline as the harvester machine travels forward to move around theside of the tree. Then, the trailing side of the shaker must be movedrapidly from engagement with the side of the tree inwardly towards thetree centerline to engage the backside of the tree. The high forcesimparted by the shaker engaging the tree results in olives flying offthe tree in all directions as the tree is shaken. As a result, theperson controlling the position of the shaker must look through aprotective screen in order to avoid being struck by olives. The screenresults in diminished visibility of the person controlling the positionof the shakers while observing the tree, the olives, and the movingshakers. In short, it is physically and mentally taxing on the operatorto reposition the shaker head for optimum fruit removal and minimum treedamage.

[0017] Various patents pertaining to harvesters are know to theinventors. U.S. Pat. No. 5,904,034 discloses a machine that has ahydraulic cylinder to bias a picking head to contact the trees. Onedeficiency in this design is that if the harvester is not on levelground the brush will be urged by gravity either in toward the treethereby generating too much force on the tree or, depending on the slopeof the ground, away from the tree and thereby not getting the contactwith the tree that yields optimum harvesting. The biasing cylinder mustbe set to a low enough pressure to avoid excessive penetration of thetree by the rods. In this patent there are no sensors for sensing thetree and then automatically adjusting the position of the shaker headrelative to the tree.

[0018] It is also known to use rods on a shaker head to harvest fruit.In U.S. Pat. No. 4,860,529 no sensors are used to sense the position ofthe tree relative to the shaker head.

[0019] It is also known to use a shaker head including a force-balancedshaker with the shaker head movable to approach at least three sides ofa tree. No sensor springs are disclosed in U.S. Pat. No. 5,661,963, andthere is no feed back system for automatically adjusting the depth ofshaker rod penetration into the tree.

[0020] It is also known to provide a harvester that has multiple shakerheads on a single chassis. In U.S. Pat. No. 5,423,166, there is noprovision for automatic positioning of a shaker head responsive tofeeler springs associated with the shaker heads.

[0021] It is also known to provide an over-the-top harvester as shown inU.S. Pat. No. 5,067,314. No sensor responsive device depending on feelersprings is taught by this patent.

[0022] Each of the above mentioned patents are hereby incorporated byreference. None of these above mentioned patents disclose a system andmethod for harvesting using shaker brushes that are sensor responsiveusing feeler springs as is disclosed herein.

[0023] A problem relating to the manual positioning of shakers is thenumber of workers required in moving the shakers in and out of positionduring operation of such a harvester. Increased operating cost isreflected in such harvesting systems because as more workers are neededto operate the machinery higher operating costs accrue.

[0024] Also a problem is the decreased fruit removal rates observed in amanual operation of a force balanced shaker harvester.

[0025] In one embodiment of this invention, an automatic steering systemis incorporated in the harvester. In prior art harvesters an automaticsteering system using a guide wire, grapevine trunk, curb edge, orvisual feedback are used. For example, one way to steer a harvester isto use side rails that sense relative tree trunk side-to-side positionand automatically direct hydraulic oil to a steering cylinder to drivean error signal towards zero to steer front wheels of the harvester.

[0026] Problems relating to steering a harvester apparatus caused by therelatively long wheelbase of the harvester need to be overcome. Awheelbase of approximately two hundred fifty inches in combination witha requirement to turn the harvester within a thirty-foot radius, themaneuvering space at the beginning and end of each tree row, createsmaneuverability issues for the harvester. To accomplish efficientturning movements in this invention, both front and rear wheels aresteerable wheels. For example, for a left turn, the front wheels turnleft while the rear wheels turn a corresponding amount to the right.This causes the harvester to turn about a centerline located along aline perpendicular to the travel and approximately halfway between thefront and rear wheels. An operator positioned at the operator's stationat the front of the harvester cannot judge the harvesters trailingposition. Thus, if the operator sharply turns at the end or beginning ofa row, the harvester rear will swing out and not line up with the treerow centered under the straddling harvester. Therefore, damage to thetree and/or machine will likely occur. If the operator selects to steerwith only the front wheels, the rear wheels will “cut over”, that is nottrack with the front wheels, with the same result (but usually on asmaller diameter of the turn) as above.

[0027] Another problem addressed by this invention concern access to theforce balanced drive device. A new mounting technique is included inthis invention wherein a collar supports the shaker brush below theforce-balanced drive. This means that access to the drive is possiblewithout having to remove the shaker brush or its substantial mountinghardware. Previously, that is in earlier designs, the support for theshaker brush was above the drive unit. This blocked access to the forcebalanced shaker unless the shaker brush support was first removed.

SUMMARY OF THE INVENTION

[0028] The present invention provides a harvester apparatus for removingfruit from a tree, bush or plant, which comprises a shaker brush carriedby the harvester. The shaker brush is capable of being automaticallymoved to alternative positions relative to the tree, bush or plant.Movement of the shaker brush or brushes is responsive to inputs fromtree contacting springs or feelers that determine the presence of a treeand the trees shape. The present invention also provides a system forsteering the harvester by providing a pair of rail sensors to indicatethe rear position of the harvester. This invention also includes amounting arrangement to mount a shaker brush driven by a force balancedshaker, in a way that does not block access to the force balanced driveunit.

[0029] The harvester performs a series of acts for removing fruit from atree, bush or plant, which includes the steps of: a) providing a shakerbrush that will contact the tree; b) providing a system of feelersprings to sense the presence of a tree; c) computing sensory inputinformation generated in response to contact between the tree and thefeeler springs; d) automatically moving the shaker brush relative to thetree and the harvester to accommodate the contour of the tree responsiveto the sensory input information.

[0030] In another embodiment of the invention, a system for steering aharvester includes a pair of rail sensors used to independently indicaterear position of the vehicle. The position of the rear wheels or theposition of the back of the vehicle, can be conveyed to the operator byeither alerting him with error lights to indicate which way he shouldturn or as input to an automatic control system, controlling a hydrauliccircuit, for the rear wheels which controls rear wheel steering.

[0031] It is an object of this invention to provide a sensor input to acontrol circuit to automatically adjust the position of the harvesterbrushes.

[0032] It is another object of this invention to have a sensor inputresponsive to feeler springs that will contact fruit trees.

[0033] It is a further object to require the input of a predeterminedtorque force from sensors before shaker brush position is affected

[0034] It is also an object of this invention to provide limitrestraints on the scope of movement of the shaker brushes.

[0035] An object of the invention is to provide rear rail sensors usedto independently indicate, and to steer, the back end of the harvester.

[0036] It is also an object of this invention to provide a four-wheelsteering device that keeps the harvester rear end aligned with the frontwheels of the harvester and more importantly with the tree row.

[0037] One more object and advantage of this invention is that a smalleroperating crew is needed to operate the harvester disclose here. Inprior units, the main operator's work responsibilities are multiplied ashe/she monitors one or more additional operators/workers performing thetask of positioning the shakers. It is an object of this invention toeliminating one operator for a single side harvesting machine or twooperators for an over-the-row harvesting machine by implementation of amachine having the control system disclosed herein. Elimination of extraoperators/workers results in inherent improvement in increased fruitremoval production and reduction in harvesting cost.

[0038] Another advantage of this invention over the conventional machineis that the potential for damage to the tree and harvesting machine from“over engagement” of the harvester with the tree is eliminated.

[0039] It is another object of this invention to provide a mountingtechnique for mounting the shaker brush to the shaker brush frame. Inprior devices, the shaker brush mounting included a substantial elementabove the force balanced shaker drive mechanism at the top of the shakerbrush. It is an object of this invention to make access to the forcebalanced shaker easier.

[0040] It is also an object of this invention to provide a support for ashaker brush along the shaker brush central shaft.

[0041] The preferred embodiments of the invention presented here aredescribed below in the drawing figures and Detailed Description of theDrawings. Unless specifically noted, it is intended that the words andphrases in the specification and the claims be given the ordinary andaccustomed meaning to those of ordinary skill in the applicable arts. Ifany other special meaning is intended for any word or phrase, thespecification will clearly state and define the special meaning.

[0042] Likewise, the use of the words “function” or “means” in theDetailed Description of the Drawings is not intended to indicate adesire to invoke the special provisions of 35 U.S.C. 112, Paragraph 6,to define the invention. To the contrary, if the provisions of 35 U.S.C.112, Paragraph 6 are sought to be invoked to define the inventions, theclaims will specifically state the phrases “means for” or “step for” anda function, without also reciting in such phrases any structure,material or act in support of the function. Even when the claims recitea “means for” or “step for” performing a function, if they also reciteany structure, material or acts in support of that means or step, thenthe intention is not to invoke the provisions of 35 U.S.C. 112,Paragraph 6. Moreover, even if the provisions of 35 U.S.C. 112,Paragraph 6 are invoked to define the inventions, it is intended thatthe inventions not be limited only to the specific structure, materialor acts that are described in the preferred embodiments, but inaddition, include any and all structures, materials or acts that performthe claimed function, along with any and all known or later-developedequivalent structures, material or acts for performing the claimedfunction.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0043] The preferred embodiments, characteristics and benefits of thepresent invention can be more easily understood from the followingdescription of the preferred, and alternative embodiments, incombination with the drawing figures, in which:

[0044]FIG. 1 is an overhead side angle view of an apparatus forharvesting fruit, e.g. olives, from a tree, bush or plant of theinvention;

[0045]FIG. 2 is a sectional view of the harvester shaker element of FIG.1, taken along 2-2;

[0046]FIG. 3 is a side view of the anchor spring from an upper portionof FIG. 2;

[0047]FIG. 4 is a top view of the shaker element of FIG. 1;

[0048]FIG. 5 is a side view of a limit switch associated with the shakerof FIG. 1;

[0049]FIG. 6 is a mechanical stop associated with the shaker of FIG. 1;

[0050]FIG. 7 is a side view of a pair of rear rail sensors of aharvester;

[0051]FIG. 8 is a view of a portion of the steering actuator for thefront wheels of the harvester shown in FIG. 1;

[0052]FIG. 9 shows a schematic of an automatic steering correctionsystem;

[0053]FIG. 10 is a view showing the shaker brush support at the top ofthe shaker brush with several rows of shaker brush rods removed forclarity;

[0054]FIG. 11 is a close up of the split clamp used to support the upperend of the shaker brush.

DETAILED DESCRIPTION OF THE DRAWINGS

[0055] The invention is an improved harvester for harvesting fruit andother harvestable commodities growing in orchards or in other tendedgrowing situations, configurations and environments. An example of aparticular embodiment is a harvester for the harvesting of olives fromolive trees. The invention will be described in the context of an oliveharvester but the inventors intend, and it should be recognized, thatthe invention pertains to similar harvesters, such as, but not limitedto, grape, raisin, citrus, coffee, nut harvesters and the like. That is,the disclosed harvester can be used for harvesting crops other thanolives and other harvesting scenarios incorporating the features of thisinvention are contemplated as being within the scope of this disclosure.

[0056] The harvester shown in FIG. 1 is a type that straddles the row ofolive trees. That is, the harvester is driven over the row of trees tobe harvested with the main frame of the harvester supported high abovethe ground on wheels. The harvester frame can be moved vertically byhydraulic rams to provide drive over clearance when harvesting. Thisparticular configuration is used in harvesters such as grape harvestersand the configuration can be used for olives as well as other crops ifthe host harvester frame is properly configured.

[0057] In FIG. 1, an olive harvester is shown as generally 10. Theharvester includes a frame 12 and at least one shaker element such as14.

[0058] In one embodiment of the invention, two shaker brushes 14 arecarried on the harvester frame 12. The shaker heads 14 are automaticallymovable to an extended position, meaning swung out away from thecenterline of the vehicle and away from the canopy of the olive trees.The terms “extending” and “retracting” used in this disclosurecorrespond to the “extended” or “retracted” displacement of a pivotingcylinder that is used to move the shaker elements 14. The shaker brushes14 are also retractable to a position relative to a centerline of thetree, bush or plant (not illustrated). The partially extended positionof the shaker brush 14 is shown in FIG. 1.

[0059] The harvester 10 includes a data acquisition system and a controlsystem that, in its simplest form, averages tree contour dimensions atvarious locations on the tree to provide for optimum shaker 14engagement with the tree. The rods or tines 16 of the shaker brushpenetrate into the canopy of the tree an optimum amount, not too deepand not too shallow, to effectuate good picking performance withoutdamage to the tree. Once the data from the tree contacting feelersprings, such as 20 in FIG. 2, is processed by the control system theharvester 10 automatically adjusts shaker 14 position—extended orretracted—to follow the tree profile contour as the harvester 10 movesdown a row of trees.

[0060] The control system also senses, via an electrical rotationsensor, when the shaker heads 14 have been retracted for a preset periodof time and automatically shuts off the control system to prevent systemattempts to continue to retract the shaker heads against stops.

[0061] The harvester and the control system for the shakers allow fortwo harvesting modes of operation of the shaker brushes 14. Theseinclude: 1) an automatic mode; and 2) a manual “jog” mode. In theautomatic mode, the control of the brushes is from “full out”, this is afully extended position to accept the widest trees, to a preset travelstop position. The stop setting or position is set by the operator tolimit the inward movement of the shaker head so that it does not travelto the fully retracted position. In situations where road travel, orother travel, is planned, the stop limit will be disengaged. This allowsfull inward or retracted brush position during travel to minimize widthof the vehicle.

[0062] As discussed further on in this specification, the control systemof the harvester 10 includes a steering control system thatautomatically compensates for the harvester being driven off acenterline of a row of trees.

[0063] Returning to FIG. 1, the harvester 10 includes steerable frontwheels 22, and steerable rear wheels 24. Steps 26 lead to an operator'sstation 30 having a steering mechanism 32 to steer the harvester 10.Placed generally intermediate of the front wheels 22 and rear wheels 24are the shaker brushes 14 (only one illustrated) pivotally attached to aframe 12 of the harvester 10. The frame comprises a plurality of rigidframe members, such as 12. These frame members and other frame membersillustrated in FIGS. 1-11 provide the host frame to which the shakerbrushes, the conveyors, the prime mover (not shown), and other operatingequipment for the harvester 10 are attached.

[0064] The shape and profile of olive trees is on the order of eightfeet wide and ten feet high. The harvester 10 can accommodate a tree ofat least this size passing through the harvester. The shaker brushes areplaced in position to profile an olive tree by the use of the feelersprings in order to facilitate removal of olives.

[0065] In FIG. 1 the front steerable wheels 22 are steered throughlinkage 34 operated by a hydraulically powered steering systemresponsive to steering inputs by the operator. Rear steering isaccomplished using back end steering linkage 36 carried on the vehicleframe 12 at the back end of the vehicle. Hydraulic cylinders 40 are usedto provide steering output after input from the operator at his station30. As will be discussed further on steering input to the back end ofthe vehicle may be automatically initiated by control signals from acontrol module.

[0066] In FIG. 2 the shaker brush assembly illustrated includes aplurality of flexible rods or tines, such as 16 that are attached to acentral substantially vertical shaft 42 as is known in the art. Aplurality of cantilevered leaf spring feelers such as 20 are carried ona vertical shaft 44 which is offset from the shaft 42 carrying theshaker rods 16. The feeler spring shaft 44 is pivotally supported onsupports or members 46 and 48 which are cantilevered away from andattached to shaker brush frame member 50. In one embodiment, the shaft44 carrying the spring feelers 20 is located in a position such that itleads, relative to forward travel of the harvester, the center shaft 42of the shaker brush assembly 14. A force balanced shaker drive system iscontained in housing 52. The flexible shaker rods, such as 16, areconnected to the central shaft 42 as is known in the harvester art.These flexible rods are vertically spaced to form levels or rows ofrods.

[0067] The verticality of the brushes is within a broad range. In apreferred embodiment the brushes will be generally vertical but it isexpected that other embodiments of the invention can incorporate brushesthat are out of vertical by a significant amount. This would be in therange of, but not limited to, five to twenty degrees from vertical.

[0068] A force balanced shaker drive reaction arm 54 is connected toupper portion of the shaker brush assembly. The arm 54 has a middleportion that angles upwardly from the end of the arm. This end of thearm is connected to the frame 12 of the harvester 10. The other end ofthe arm extends horizontally to where it is connected to the shakerdrive motor 58. The shaker drive motor is rigidly coupled to the shakerdrive shaft 68.

[0069] The brush rods 16 may be oriented at a ninety-degree anglerelative to the central shaft 42, or slightly offset at a vertical orhorizontal angle if desired. The spacing distance between adjacent rodsis configured to optimize the engagement of the shaker brushes 14 withthe tree profile for efficient olive harvesting. The spring feelers,such as 20, assist in guiding the shaker head 14 into the tree bycontacting the tree and assisting in determining the general profile,shape or contour of the tree.

[0070] The springs or feelers, such as 20, are cantilevered from theirsupport shaft 44. The mounting apparatus for mounting the spring feelersis an adjustable collar 56, the collar being a split ring attached to aspring attachment plate, that fits over the support column 44. Thesprings 20 and associated mounting collars, such as 56, can beindividually rotated and clamped to the center pivot rod or column 44.These feelers are located at approximately a ninety-degree anglerelative to the support column 44 in a horizontal plane. The feelers arespaced vertically above or below each other so that there are enoughfeelers to contact the tree at multiply places. The feelers 20, referredto herein as springs, spring feelers, or feeler springs, are resilientbut stiff enough to generate a torque load on their support column 44when the feelers 20 are “brushing” against a tree.

[0071] The length of the feelers, such as 20 depends on the shape of thetrees to be harvested. As shown in FIG. 2, the springs or feelers 20 atthe upper part of the tree are usually longer than the lower feelersthat will contact a broader portion of the tree. The individual feelers20 can be replaced with different length feelers (items 20 are shown asthree different lengths) that are either shorter or longer than theremoved one depending on the expected tree profile. For example, feelers20 designed for a conical shaped tree profile, wherein the feelerstoward the top of the shaker brush are for sensing the top of the tree,are longer than lower feelers, which will contact the wide part of thetree, can be replaced with a full set of shorter feelers for a hedgerowshaped, generally straight sided or vertical profile. The spacingdistance between adjacent feelers, such as 20 is set to optimize theengagement of the shaker brush 14 into the tree profile. The horizontaloptimum distance between each feeler is determined empirically but wouldbe approximately eight to eighteen inches.

[0072]FIG. 3, which is the content of the FIG. 2 drawing in the circleidentified as “3”, shows the rod or spring feeler support column 44connected to a slotted tube previously identified as a support 46. Thesupport 46 also supports a plate 60. A spring anchor 62 is Z-shapedpiece of flat stock having a spring connection end 64 that extends outfrom the side of the support 46. The spring anchor 62 is fastened to thesupport firmly. A spring 66 is connected at one end to the spring anchorat 64 and at a second end to a movable tab 70. The tab 70 is anotherZ-shaped piece of flat stock similar to anchor 62 but it is not fastenedto the support 46. It is firmly affixed to the shaft 44 for the feelersprings and will move with that shaft, resisted by the spring 66.

[0073] Also shown in FIG. 3 is the shaft 44 and the rods such as 16. Theshaft 44 is restrained from downward vertical movement by the interfaceof the movable tab 70 contacting the top surface 72 of the support 46.The bottom edge 74 of the movable tab 70 will be the contact surface forthe tab 70. The tab 70 is attached to the shaft 44 however thatconnection is not visible in FIG. 3.

[0074] A bearing 76 locates the shaft 44 for the feeler springs 20 at anupper support 46.

[0075] It should be noted that the spring anchor 62 and the movable top70 are provided with holes such as 80 that allow spring 66 to beattached in different locations. Moving the spring attachment oranchoring will result in a degree of tension adjustability.

[0076] A potentiometer, as represented by housing 82, is shown in thisfigure in line with the end of the feeler spring shaft 44.

[0077] Item 84 is the end of a support that supports and stabilizes theupper end of the central shaft 42. More about this support will bedescribed below.

[0078]FIG. 4 is helpful in recognizing the placement of the elementsshown in FIG. 3. The force-balanced shaker housing 52 hides part of therods such as 16 that emanate from the central shaft.

[0079] The feelers or springs 20 are clearly shown in this version ashaving different lengths and different angular rotation or position onthe shaft to which they are mounted. However, spring length is avariable that is selected based on picking effectiveness dependent ontree shape. The springs 20 are mounted to the shaft 44. The shaft ishidden under the potentiometer housing that is mounted to plate 60. Thisplate is mounted to upper support 46. Spring anchor 62 is also mountedto the support 46 and the other end of spring 66 is affixed to movabletab 70 which will move with the shaft 44 as the tab 70 is fixedlyattached thereto.

[0080] The upper support 46 is attached to the wall of the tube 50, alsoreferred to as the shaker brush frame member, and will move with it.

[0081] The entire shaker brush assembly will pivot around point 86. Thearm 54 at the top of the shaker brush above the force-balanced shaker 52is primarily a resisting stabilizer that resists the force balancedshaker motor drive torque. It is not used as the upper support for thecentral vertical shaft 42. That function is related to the brush shaftsupport 84 and will be discussed below.

[0082] Also shown in FIG. 4 is hydraulic cylinder 90 which is pivotallyattached to a portion of frame member 12, at the piston end of thecylinder. The rod end is pivotally attached to a structural elementother than the arm 54. This cylinder 90 will “extend” and “retract” theshaker brush 14 responsive to signals sent to the hydraulic valve systemby the controller responsive to the spring feeler input, override limitcontrols or operator override controls. The hydraulic cylinder will beplumbed to a hydraulic pump and source of fluid pressure and flowthrough suitable hydraulic lines (not shown).

[0083] The operation of the tree locating spring feelers is as follows.The feelers 20, when in contact with a tree, will generate a torque loadon the shaft 44. The torque input of one feeler 54 engaging a treecauses relatively little shaft 44 rotation due to the resistance of thespring 66. However, engagement of several feelers 20 will cause anadditive torque effect with resultant greater torque effect on shaft 44.The shaft 44 will then rotate a greater degree causing the anchor spring66 to be stretched beyond its preload setting. The potentiometer willgenerate a signal responsive to shaft 44 rotation. As an alternative,the potentiometer may be side mounted with a suitable belt or chaindrive (neither being illustrated) to cause a shaft from thepotentiometer to rotate in direct proportion to rotation of the shaft 44in response to torque on the spring feelers. Another alternative is touse a linear motion potentiometer or slide potentiometer for sensing thedegree of support shaft rotation.

[0084] The rotation of the shaft 44, to which the feeler rods areattached, causes a signal to be sent to an electronic controller locatedon the vehicle, most usually in the operator's workstation. Theelectronic controller in turn causes the extension or retraction of thehydraulic cylinder 90, powered by a hydraulic pump remote from thecylinder and appropriately plumbed thereto, to move the shaker head inor out relative to the centerline of the harvester. Repositioning theshaker brush 14 drives the potentiometer 82 error signal toward zero.This repositioning establishes a new equilibrium point that helpsdetermine whether the shaker 14 needs to be adjusted in response todifferent tree profiles.

[0085] In summary of the invention to this point, the harvester employsa method of positioning a shaker head of the harvester relative to theframe. The shaker head includes a shaker brush frame, a rotatable feelerspring shaft, a feeler spring supported on the rotatable feeler springshaft, a sensing device associated with the rotatable shaft for thefeeler springs, a controller having signal receiving and signalgenerating systems, and an adjustable link carried between the shakerbrush frame and the frame of the harvester. The method of shaker headpositioning includes the acts of: moving the feeler spring; sensingmovement of the feeler spring; generating an input signal correspondingto the sensed movement of the feeler spring or at the feeler springshaft; receiving the signal at the controller; and generating a signalat the controller and sending the signal to the adjustable link. In oneembodiment of the invention, the sensing of the movement of the feelerspring is done by sensing an “average” movement of the feeler springshaft caused by engagement of one or more than one of the attachedfeeler springs.

[0086] If a tree is off-center due to a steering error or poor alignmentof the harvester relative to tree, the shaker brushes will both move toaccommodate the actual position of the tree. It is contemplated that thesystem can be fine tuned to have only one brush move in this situationbut the preferred embodiment is to move both the left and right sidebrushes independently depending on sensed errors. A “time-out” featureis incorporated in the shaker head position control system. If theharvester is driven away from the tree row and there are no trees toengage the feelers there is no reason to keep the system in an activemode. In an active mode the system will be biased to retract thehydraulic cylinders and move the shaker heads as far inward as possible.When there is a lack of torque on the feeler spring shaft 44 there willbe a constant error signal. If this signal is present for more than aset time, e.g. ten seconds, the control system will send a signal to ahydraulic control valve and the hydraulic pressure to the cylinder iscut off. Basically, the time out feature automatically turns the shakerhead control system off when control of the shaker head position is notneeded. As a result hydraulic pressure and flow to and from the controlvalves, hydraulic hoses and actuators for the shaker head will becurtailed.

[0087] Whenever the error signal computed by the control systemindicates a need to change from “retract” to “extend”, the controlsystem is automatically restarted. This automatic engagement of theshaker brushes reduces wear and tear of the harvester 10. A furtherbenefit of the time out feature and automatic restarting is that theoperator of the harvester is not required to turn the system on or offas he drives into and away from contact with rows of crop due to theautomatic restart feature of the invention.

[0088]FIG. 5 and FIG. 6 show two embodiments of feeler spring and shakerbrush travel limiting solutions. The purpose of the limit apparatus isto prevent the rods 16 from one set of brushes from getting too close tothe set of rods of a second shaker brush. The rods can be separated by apreset value such as eight to ten inches from each other by either ofthese shaker head travel limiting solutions.

[0089]FIG. 5 shows one embodiment. It includes a limit switch 92 mountedon the bottom of a horizontal channel 94 which is attached to the lowerend of the major support member 96. It should be pointed out that themajor support member 96 descends down from the frame 12. It is a largebox structure beam that supports the shaker brush 16 through the shakerbrush member 50 which is pivotally mounted to the major support member.The pivot shaft is item 100 in FIGS. 5 and 6. This shaft 100 is fixed tothe shaker brush frame member alignment support 102 and can rotate in abore in the horizontal channel 94. Returning specifically to FIG. 5, acam 104 is mounted on the pivot shaft 100. The rotation of the pivotshaft rod and cam 104 trips the limit switch 92 at a predetermineddisplacement. The limit switch 92 is connected by electrical conduit 106to an input for the controller, also known as the control system module.

[0090] In FIG. 5 the shaker brush is in a partially extended position asshown in FIG. 4. As the shaker brush 14 is retracted the frame member 50will rotate or travel more inboard and eventually limit switch 92 willbe triggered and send a signal to the controller to stop movement byclosing a supply valve to the hydraulic cylinder 90.

[0091] The feeler springs 20 for engaging the tree are shown in FIG. 5.If the shaft for the feelers 44 does not rotate due to the lack ofengagement of the feelers 20 with a tree profile, the shaker heads willretract as the potentiometer 82 will indicate no shaft displaced and thecontroller will attempt to bring the shaker brushes inboard to “find” atree. The limit switch 92 is used to interrupt the retract signal at apreset position to prevent the shaker head 16 from fully retracting,that is, beyond the need for harvesting or close to the other shakerbrush. For road travel the limit switch 92 can be switched off andoverridden from the operator's station. This allows the shakers 16 tofully retract to minimize overall width of the harvester when travelingor at rest.

[0092] The second travel limiting solution is shown in FIG. 6.

[0093]FIG. 6 shows a mechanical limit structure that operates throughthe feeler shaft 44. An adjustable collar 110 is affixed to one end of asensor paddle 112. The sensor paddle 112 will move freely with shaft 44until it contacts the major support member 96. It will, upon suchcontact, impose a torque load on the shaft 44, rotate the shaft 44 toaffect potentiometer output at the end of the shaft (82 in Fig.4) to actas a surrogate input when there is no torque on the shaft 44 beinginduced by the spring feelers 20.

[0094] The sensor paddle 112 can be manually adjusted so that eachshaker brush will not retract too far-not so far as to contact theadjacent/opposite shaker brush, for instance.

[0095] Also shown in FIG. 6 is the lower support 48 and its alignmentbearing 114.

[0096] For road travel, the sensor paddle 112 may be rotated so that itwill not contact the major support member 96. This will allow the shakerbrushes 14 to fully retract to minimize the harvester width whentraveling or when parked.

[0097] Mention of a controller has been made several times in thespecification. The controller is a dedicated microprocessor that willreceive inputs from several sensors and control several output options.One input to the controller is a voltage signal from the potentiometer82. Another input could be from the limit switch 92. The input fromthese sources will be processed by the controller and various outputs,one example is the outputting of signals to the electric-over-hydraulic,solenoid operated valves for controlling the position of the shakerbrushes 14 through the hydraulic cylinders such as 90.

[0098] The controller also will be used in the rear wheel steeringcontrol scheme as will be discussed further on.

[0099] The controller is not to be limited to these functions asmicroprocessors of this type are programmable to be verymultifunctional. For instance, but without intending to be limiting, thecontroller can be used to control the height of the vehicle-it iselevatable on hydraulic rams at each wheel station of the harvester. Thecontroller can also be used to control the height of the operator'sworkstation, the speed of the shaker brush drive system and various dashboard indicators and lights as are necessary or informative for theoperator.

[0100] The controller, with respect to shaker brush position, can beswitched from an auto mode, the normal harvesting mode, to a jog mode.In the latter condition, the operator can use a jog switch to move andhold each shaker brush 14 at any desired position.

[0101] One example of harvester operation follows. The harvester 10 isdriven down a row of olive trees to shake the trees at a magnitude andfrequency sufficient for olives to be picked and fall onto the catch andrecovery apparatus carried on the lower part of the harvester frame. Forexample, as depicted in FIG. 1, the operator need only to climb up theset of stairs 26 provided at the front of the harvester 10 and steer theharvester down a row of trees, steering the harvester to straddle thetrees. One or more shaker brushes 14 are engaged with the branches ofthe trees and are able to determine, using the feeler springs 20associated with each shaker head, the profile or the shape of the treefor optimum shaker engagement. Feeler springs such as 20 attached to thefeeler shaft 44 and communicating with the control system, automaticallyrepositions each shaker head 14 to properly engage the shaker rods 16with a tree. See FIGS. 2-4. If no engagement with a tree is warrantedthe shaker brushes 14 are withdrawn toward the frame 12 of the harvester10 to minimize its width for easier transport.

[0102] The harvester can also be equipped with a sensor system to helpthe operator in steering of the vehicle. The sensor system is an aid insteering the back end of the vehicle so that as the vehicle swings widein turns it can be properly steered to avoid tree damage or otherdetrimental conditions caused by the rear of the vehicle not trackingthe front of the vehicle.

[0103]FIG. 7 is a bottom view of one side of the conveyor and olivegathering apparatus, generally 116, carried at the lower portion of theharvester 10. Direction of travel will be relatively upward in thisfigure. A mirror image comprising a right side conveyor and gatheringapparatus would be installed on the harvester but has been left out ofFIG. 7 for clarity.

[0104] An olive tree trunk is shown as 120. The tree trunk will bebracketed on the left and right by the apparatus 116 and the minor imageunit on the other side. A longitudinal frame member 122 runs the lengthof the catch apparatus 116. This frame member 122, as well as others,supports the conveyor system, the pivotal flaps 124, a guard bar 126 aswell as other apparatus.

[0105] A linkage supported front rail 130 is carried by parallel links132 and 134 on the frame member 122. The front rail is spring biased byroller contact 136 and biasing rod 142 to move outboard relative to theframe member 122, toward the center of the harvester which is toward thetrees. As this front rail 130 is displaced toward the frame 122,responsive to contact with an obstruction such as a tree, a sensorassociated with the front rail will indicate to the controller that theharvester is being driven off a proper path, too close to a tree orotherwise in an undesirable direction. The sensor, a first linearpotentiometer, pictorially represented as 140, is associated withbiasing rod 142. The biasing rod 142, with the roller 136, is springloaded by means of a spring (not shown) behind a frame member to urgethe front rail 130 toward the center of the vehicle. The position of thefront rail 130 will be sensed by the linear potentiometer 140 and acorresponding signal sent to the controller. If the front rail 130 isbeing deflected by a tree, post or other impediment, a signal will besent to the operator informing him that a steering correction isrequired. Alternatively, an automatic steering correction could be madeby the controller sending a signal to activate a steering valve for theharvester front wheels.

[0106] The back end of the harvester 10 also has steerable wheels. Animprovement to existing harvesters is to have the rear wheelsautomatically steered in response to the sensing of a back end steeringdeviation. In FIG. 7 a linkage supported back rail 144 is mountedsimilarly to the mounting of the front rail addressed above. A shaftmounted roller 146 is carried at the end of a spring loaded shaft 150that will bias the back rail 144 toward the centerline of the harvester.The second linear potentiometer 152 will sense the position of the shaftand thus the back rail 144. If a significant, out of tolerancedeflection is sensed, the signal from the potentiometer 152 to thecontroller will be processed and send a signal to the operator, such asa light on the dash, instructing that a rear steering correction isneeded and showing which direction a correction should be made. Inanother embodiment, the controller can be programmed and set to delivera signal to the back end steering system control valves.

[0107]FIG. 1 in conjunction with FIGS. 8 and 9 illustrate the automaticrear steering embodiment. Looking first at FIG. 1, the back or rearsteering hardware can be seen. The cylinders 40 will both be used tosteer. They will urge the pitman arms 154 and 156 to rotate the verticaluprights clockwise or counterclockwise depending on which steeringvalves are activated. A tie rod 160 serves as an equalizer. The actualvalving, hydraulic pump, reservoir and necessary hydraulic conduct andelectrical conduit are not shown as they are known in the art. FIG. 8provides a closer view of the steering mechanism. It is virtually thesame as the rear steering apparatus with a pitman arm 162, a tie rod 164and a steering cylinder 166. Not shown in FIGS. 1 or 8 is a linearmotion detecting potentiometer, or the like, carried inside or outboardof at least one of the steering cylinders, or tie rods, at each end ofthe vehicle. Such device would indicate electronically the static anddynamic position of the steered wheels at the respective ends of theharvester and convey that information to the controller.

[0108] In FIG. 9, the controller, a programmable microprocessor that maybe equipped with onboard valve driver amplifiers, will receive variousinputs from, for instance, a left side second linear motionpotentiometer 172, not shown in the other drawings figures, and will beelectronically connected to the controller 170 as shown. Another sensorinput to the controller 170 is the steering activator master positionsensor 174 that is associated with the front steering linkage asdiscussed above. A further sensor will be the rear steering activatorslave position sensor 176.

[0109] The controller 170 will provide electrical control signals toboth the front steering valve 180 and the rear steering valve 182. Thesevalves are conventional solenoid operated three position hydraulicvalves, either on/off, or proportional, which receive fluid flow from apump 184. Appropriate steering motors, such as cylinder 186 for steeringthe front wheels ant cylinder 188 for steering the rear steering wheelsare shown in FIG. 9

[0110] In one mode of automatic steering, when an error signal isreceived from the rear position sensors 152 or 172 (linear motionpotentiometers), the signal processed through the controller 170,overrides the current control and signals a rear wheel actuator orsteering motor 188 to reposition rear wheels 24 to drive the rearposition signal from the linear potentiometers 152 or 172 toward zero.When this condition is met, a conventional master/slave steeringrelationship or manual rear steering is automatically resumed.

[0111] The steering system performs with an automatic coordinatedfour-wheel steering arrangement. The system can work equally well withmanual two wheel, four-wheel, or crab type steering system. Theautomatic priority rear wheel correction activated from the secondlinear potentiometers associated with the position of the rear rails isrepresentative of one aspect of the invention.

[0112] In summary, this steering correction aspect of the invention isincorporated in a harvester having two pairs of steerable wheels, eachpair of steered wheels has a sensing device for determining the positionof the steered wheels and a hydraulic circuit including valve systemsfor steering the harvester. One improvement in the harvesterincorporates a system including a linkage supported rear rail carried bya frame of the harvester; a sensing device sensing the lateral positionof the rear rail; and a controller responsive to a sensed signal fromthe sensing device. In this system the controller will cause thehydraulic circuit valve system to position the pair of steerable wheelsso that the sensing device sensing the lateral position of the rear railindicates that the rear rail is in a predetermined position. The methodof doing this is accomplished by carrying out the following steps: (a)sensing the position of the linkage supported rear rail; (b) sending thesensed position of the rear rail to the controller; (c) determining, inthe controller, if a steering correction is necessary; (d) sending asignal to the steering system; (e) sensing the position of the steerablewheels; (f) determining, in the controller, if a steering correction isnecessary; (g) repeating acts (a) through (f) until the controllerdetermines that a steering correction is not necessary.

[0113] The harvester presented herein includes stabilized shaker brushesor shaker heads 14 that are mounted so that access to the force balancedshaker 52 is not impeded or hampered. As shown in FIG. 2 the shakerbrush assembly, generally 18, has a central shaft 42. This shaft issupported at its lower end on arm 190 which is securely attached to theend portion of the box section tubing shaker brush frame member 50. Atthe upper portion of the central vertical shaft 42 there is a brushshaft support having an end 84. This support is fixedly attached to theupper portion of the shaker brush frame member 50. As shown more clearlyin FIGS. 10 and 11 a clamp 192 is positioned around the central shaft42. The clamp 192 is a split clamp such that clamp half 194 is removablyattached to clamp half 196 which is fixedly mounted to the brush shaftsupport 84. The clamp 192 supports the shaft 42 by cam bearings 200carried by each half of the clamp 192. The clamp 192 is not necessarilya precision fit around the central shaft 42. It is secure but the clamphalves can be semiflexably held together by bolts passing through theattachment bosses such as 202 and 204 which could incorporate aspring-like distance piece, such as a belleville washer, placed under anattachment bolt head or bolt nut, both shown, or even between the clamphalves at the attachment bosses (not shown). With this upper“stabilizer” used to stabilize the shaker brush in a vertical deploymentit is not necessary to have a significant stabilizer at the uppermostend of the central shaft as was done in earlier harvesters of this type.With this improvement, access to the force balanced shaker, for routineservicing, does not require the removal of the shaker brush unit itselfas was the situation with the prior devices.

[0114] In summary of this aspect of the invention, the support for theshaker brush includes a shaker brush frame comprising a shaker brushframe member; an arm attached to one end of the shaker brush framemember; a brush shaft support carried on the shaker brush frame memberspaced apart from the arm at one end of the shaker brush frame member; aclamp, having an inside diameter, carried by the brush shaft support,the clamp having two halves fastened together; a plurality of frictionreducing elements carried by the clamp, each friction reducing elementhaving a contact point inside the inside diameter. This system willallow supporting the central shaft from the lower end thereof andsupporting the central shaft in the shaft zone using the clamp.

[0115] Various of the features, subcombinations and combinations of thisinvention can be practiced with or without reference to other features,subcombinations and combinations of the invention, and numerousadaptations and modifications can be effected within the spirit of theinvention. While particular embodiments of the invention have been shownand described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from theinvention in its broader aspects, and, therefore, the aim in theappended claims is to cover all such changes and modifications as fallwithin the spirit and scope of the invention and the following claims.For instance, a plurality of stepper motors can be used as sensors andactuators in several places in the apparatus. In addition, for instance,the feeler springs can be made of different materials such as variousmetals, plastics, fiberglass or other similar materials. Such designnuances are contemplated as being within the scope of the invention andintend to be covered by these claims.

What is claimed is: 1) A harvester shaker assembly comprising: a centralshaft supported on the shaker assembly; a plurality of rods projectingfrom the central shaft; a rotatable feeler spring shaft supported on theshaker assembly; a plurality of feeler springs attached to the feelerspring shaft. 2) The invention in accordance with claim 1 wherein therotatable feeler spring shaft is a shaft extending parallel to thecentral shaft. 3) The invention in accordance with claim 1 wherein thefeeler springs extend beyond the ends of the rods projecting from thecentral shaft. 4) The invention in accordance with claim 1 wherein thefeeler springs do not contact the rods. 5) The invention in accordancewith claim 2 wherein the rotatable feeler spring shaft is connected to aposition sensor. 6) The invention in accordance with claim 5 wherein theposition sensor is an electrical position sensor. 7) The invention inaccordance with claim 6 wherein the position sensor is a potentiometerresponsive to the position of the rotatable feeler spring shaft. 8) Theinvention in accordance with claim 1 wherein the plurality of feelersprings include feeler springs of a first length and feeler springs of asecond length. 9) The invention in accordance with claim 8 whereinfeeler springs of the first length have a given width and are separatedfrom springs of the second length on the feeler spring shaft by morethan the width of the feeler springs of the first length. 10) Theinvention in accordance with claim 1 wherein the feeler springs includefeeler springs having a first spring rate and feeler springs having asecond spring rate. 11) The invention in accordance with claim 1 furthercomprising a shaker brush frame member. 12) The invention in accordancewith claim 11 wherein the central shaft is supported on the shaker brushframe member. 13) The invention in accordance with claim 12 wherein thefeeler spring shaft is supported on the shaker brush frame membergenerally offset from the central shaft. 14) The invention in accordancewith claim 13 further comprising: a vehicle having a frame to which theshaker brush frame member is pivotally attached; a control unit capableof receiving sensor input signals and capable for sending controlsignals; a position sensor sending a signal to the control unit; anadjustable link mounted to the vehicle frame at one end of theadjustable link and to the shaker brush frame member at a second end ofthe adjustable link. 15) The invention in accordance with claim 14wherein the adjustable link is adjusted in response to actuation signalsfrom the control box. 16) The invention in accordance with claim 15wherein the position sensor is connected to the rotatable feeler springshaft. 17) The invention in accordance with claim 16 wherein therotatable feeler spring shaft comprises an elastically deformablerestraint. 18) A feeler spring having a height, a length and a width,where the length is greater than the combined height and widthcomprising: a bracket attachment location at an end of the feelerspring. 19) The invention in accordance with claim 18 further comprisingan attachment bracket attached to the bracket attachment location of thefeeler spring. 20) The invention in accordance with claim 19 wherein theattachment bracket comprises an adjustable collar. 21) A method ofpositioning a shaker head of a harvester relative to a frame of theharvester, the shaker head having a shaker brush frame, a rotatablefeeler spring shaft, a feeler spring supported on the rotatable feelerspring shaft, a sensing device associated with the rotatable shaft forthe feeler springs, a controller having signal receiving and signalgenerating systems, an adjustable link carried between the shaker brushframe and the frame of the harvester; the method comprising the acts of:moving a feeler spring; sensing movement of the feeler spring;generating an input signal corresponding to the sensed movement of thefeeler spring; receiving the signal at the controller; generating asignal at the controller and sending the signal to the adjustable link.22) The method as set forth in claim 21 wherein the adjustable link is ahydraulic cylinder and the harvester includes a hydraulic system toallow the extension or retraction of the adjustable link. 23) The methodas set forth in claim 22 further comprising a limit stop wherein thelimit stop sends a signal to the controller. 24) The method of claim 23wherein the controller will send a signal to the hydraulic system tostop the retraction of the hydraulic cylinder when the limit stop signalis received by the controller. 25) A harvester for harvesting fruit, theharvester having two pairs of steerable wheels, each pair of steeredwheels having a sensing device for determining the position of thesteered wheels, and a hydraulic circuit including valve systems, forsteering the harvester, the improvement in the harvester comprising: alinkage supported rear rail carried by a frame of the harvester; asensing device sensing the lateral position of the rear rail; acontroller responsive to a sensed signal from the sensing device,whereby the controller will cause the hydraulic circuit valve system toposition the a pair of steerable wheels so that the sensing devicesensing the lateral position of the rear rail indicates that the rearrail is in a predetermined position. 26) The invention in accordancewith claim 25 wherein the sensing device is a linear potentiometerresponsive to the lateral position of the rear rail relative to theframe of the harvester. 27) The invention in accordance with claim 25further comprising a sensor carried on the harvester to sense thesteering direction of the steerable wheels. 28) The invention inaccordance with claim 27 wherein each pair of steered wheels isassociated with a sensing device to sense the direction of each pair ofsteerable wheels, the sensor output being directed to the controller.29) The invention in accordance with claim 28 further comprising alinkage supported front rail. 30) A method of steering a harvester, theharvester having steerable wheels, a linkage supported rear rail, acontroller, a sensor sensing the position of the rear rail, a steeringsystem for steering the wheels, a sensor associated with the steerablewheels, the act of steering the harvester including the steps of: (a)sensing the position of the linkage supported rear rail; (b) sending thesensed position of the rear rail to the controller; (c) determining, inthe controller, if a steering correction is necessary; (d) sending asignal to the steering system; (e) sensing the position of the steerablewheels; (f) determining, in the controller, if a steering correction isnecessary; (g) repeating acts (a) through (f) until the controllerdetermines that a steering correction is not necessary. 31) A shakerbrush frame comprising: a shaker brush frame member; an arm attached toone end of the shaker brush frame member; a brush shaft support carriedon the shaker brush frame member spaced apart from the arm at one end ofthe shaker brush frame member; a clamp, having an inside diameter,carried by the brush shaft support, the clamp having two halves fastenedtogether; a plurality of friction reducing elements carried by theclamp, each friction reducing element having a contact point inside theinside diameter. 32) The invention in accordance with claim 31 furthercomprising a shaker brush assembly carried by the shaker brush framewith one end of the shaker brush assembly supported on the arm and theshaker brush assembly supported by the clamp. 33) The invention inaccordance with claim 32 wherein the shaker brush assembly includes acentral shaft and the central shaft is supported by the clamp. 34) Amethod of supporting a shaker brush, the shaker brush including acentral shaft having a lower end and having an upper end and a shaftzone between the lower end and the upper end, in a shaker brush frame,the shaker brush frame also including a bearing incorporating clampsupported on an arm attached to the shaker brush frame, comprising theacts of: supporting the central shaft from the lower end thereof;supporting the central shaft in the shaft zone using the clamp. 35) Themethod of claim 34 further comprising a force balanced shaker mounted tothe shaker brush frame above the clamp attachment point in the shaftzone of the central shaft. 36) A harvester shaker assembly comprising: acentral shaft; a plurality of rods projecting from the central shaft; arotatable feeler spring shaft; a plurality of feeler springs attached tothe feeler spring, shaft; spring, connected to the rotatable feelerspring shaft and to the harvester shaker assembly for providingresistance to rotation of the rotatable feeler spring shaft. 37) Aharvester having a shaker assembly for harvesting fruit, the harvesterhaving two pairs of steerable wheels, each pair of steered wheelshaving, a sensing device for determining the position of the steeredwheels, and a hydraulic circuit including valve systems for steering theharvester and a shaker positioning hydraulic system; the improvement inthe harvester comprising: the shaker assembly having central shafthaving a plurality of rods projecting from the central shaft; arotatable feeler spring shaft carried by the shaker assembly, the feelerspring shaft having a shaft rotation sensor for generating a signal; aplurality of feeler springs attached to the feeler spring shaft; alinkage supported rear rail carried by a frame of the harvester; asensing device sensing the lateral position of the rear rail; acontroller responsive to a sensed signal from the sensing device andfrom the sensed signal from the shaft rotation sensor, whereby thecontroller will cause the shaker positioning hydraulic system toposition the shaker assembly responsive to the shaft rotation sensor ofthe rotatable feeler spring shaft and cause the steering hydrauliccircuit valve system to position a pair of steerable wheels so that thesensing device sensing the lateral position of the rear rail indicatesthat the rear rail is in a predetermined position. 38) The invention inaccordance with claim 37 wherein the shaker assembly comprising: ashaker brush frame member; an arm attached to one end of the shakerbrush frame member; a brush shaft support carried on the shaker brushframe member spaced apart from the arm at one end of the shaker brushframe member; a clamp, having an inside diameter, carried by the brushshaft support, the clamp having two halves fastened together; aplurality of friction reducing elements carried by the clamp, eachfriction reducing element having a contact point inside the insidediameter.